The UK Space Agency’s report on the SKYLON technical assessment, for which the European Space Agency (ESA) was commissioned, has concluded that it could not find anything that would prevent successful continued development of SKYLON and agreed with objectives of the proposed next stage of the development program.

SKYLON is an unpiloted, reusable single stage to orbit (SSTO) spaceplane that will provide reliable access to space and be capable of delivering payloads of up to 15 tons into Low Earth Orbit (LEO, approx. 300km) at about 1/50th of the cost of traditional expendable launch vehicles, such as rockets. SKYLON’s SABRE engines use liquid hydrogen combined with oxygen from the air at altitudes up to 26km and speeds of up to Mach 5 before switching over to onboard liquid oxygen for the final stage of ascent.

The UK Space Agency’s commissioned report concluded that ‘no impediments or critical items have been identified for either the SKYLON vehicle or the SABRE engine that are a block to further developments’.

Dr David Parker, Director of Technology, Science and Exploration at the UK Space Agency, said, "Both SABRE and SKYLON are exciting new technologies which could transform access to space. ESA's positive assessment should give everyone increased confidence that Reaction

The UK Space Agency’s technical assessment process was comprised of two parts. The first was a series of visits by technical experts from ESA to review Reaction Engines’ designs and witness critical tests of component performance.

The second part was the SKYLON System Requirement Review, held in September 2010, at which almost 100 international aerospace experts posed questions and made comments on SKYLON’s technical and economic feasibility. “The review ended with a consensus that no technical or economic impediments to the development of SKYLON or SABRE had been found.”

Reaction Engines consider the review a success, and its spaceplane is attracting renewed interest from the international aerospace community.

Alan Bond, inventor of the SABRE engine and Reaction Engines’ Managing Director, commented: “Space has many things to offer humanity, but the sheer expense of rockets, which have served us well in the past is inhibiting the growth of commercial activity in space.”